1. Hyperbaric Chamber Overview
Michael J. Natoli
Center for Hyperbaric Medicine and Environmental Physiology
Duke University Medical Center
Durham, NC 27710

2. Hyperbaric Surgery & Research at Duke, 1963-67
History – Europe Boerema, Hyperbaric surgery, Hyperbaric Oxygen, FG Hall how to work in the environment – Hypobaric – altitude physiology helped to develop pressure suits, in WWII.

3. F.G. Hall Laboratory, 1968 Initial chamber installed at Duke in 1963.
F.G. Hall Laboratory was completed in 1968 with six person-rated chambers (1000 fsw to 100,000 ft altitude).
Dr. Herbert Saltzman was original laboratory director.
Two chambers added in 1978 to allow hyperbaric exposures to 3600 fsw.
Depth record person dive to 2250 fsw completed in days to compress, 1 day at depth, 30 days of decompression (record stood for over nine years).
Renamed Center for Hyperbaric Medicine and Environmental Physiology in 1998.
A,B and C chambers used clinically; D,E,F,G and H chambers used for research

4. Seven Multiplace Chambers
Main Deck
Second Deck
Golf
Golf
Foxtrot
Delta
Echo
Charlie
Bravo
Alpha

5. Pipe Color Coding - US Navy
Oxygen
Nitrogen
Helium
Air
Exhaust
Vacuum
Potable Water
Fire system
Color coding
Oxygen - green
Nitrogen - gray
Helium - buff
Air - black
Exhaust - silver
Vacuum - yellow
Potable water - blue
Fire suppression water - red
Paint
Epoxy paint (zinc containing)
Imron (Dupont)
Phenoline (Carboline)
or other epoxy paint
Pressurize chamber three times to max. depth for eight hours each time
Wait 72 hours, draw gas sample

6. Alpha Chamber

7. Compressors
Three Norwalk compressors built in 1936, used in the Navy, and surplused after WWII. Each has over 19,000 hrs of operation. Each outputs 100 cuft / min.

8. Air Storage Banks

9. Control Console
Don Bordeaux, 2005

10. Internal Environmental Control
Pneumatic
valves
Muffler
Cold water
Heating / Cooling
Coils
Hot water
Lubrication
level
Blower
Internal system
Water-filled heat exchanger beneath flooring
Blower motor is outside the chamber
Reduces noise
Eliminates heat and spark potential of the electric motor
Penetrates the chamber hull through a water cooled shaft seal
Electric motor
Air flow
Shaft seal
Temperature
indicator
Thermistor

11. External Environmental Control
Blower
Thermistor
Temperature
controller
Need Picture
External system
Water-filled heat exchangers, CO2 absorbent.
The tubing is rated to an equivalent pressure to that of the chamber.
The CO2 absorbent canister may be isolated in order to change the absorbent when it is exhausted.
Cold water
CO2 absorbent
Hot water

12. Breathing Gas Systems BIBS Panel
Built in Breathing System
Inline micron filters from high pressure sources cleaned annually

13. Liquid Oxygen and Nitrogen
No ball valves in systems of > 125 psi
Liquid tank contains 900 gallons ~ 100,000 scuft
Lasts about two months
Piping must be O2 cleaned
Use non-hydrocarbon based lubricants such as fluorocarbons or halocarbon or krytox
Soft goods need to be replaced more often than in air systems – viton is used as opposed to BUNA N or rubber
Aviator grade > USP medical > Industrial
Liquid N2
Contains 3600 cu ft at 200 psi
Reduced to 120 psi

14. Oxygen Delivery Head tent Face mask Mouthpiece “T” piece Ambu-bag
Scott Duo-seal
Single hose
Overboard dump
Plastic disposable
Mouthpiece
“T” piece
Ambu-bag
Ventilator
Oxygen delivery
Plastic disposable face masks are loose fitting and should not be used at pressure
T-pieces are used for patients with endotracheal tubes
Ambu-bags are used during compression and decompression

15. Oxygen Delivery - Recirculating Head Tent
Eduction
Oxygen
Purge
Venturi
Eduction
Line 30 20 40
Purge 10 50
Sample
Line 60
Venturi
Sample
Line
Bubbler
Recirculating head tent system
Employs a venturi to increase flow and create a suction
Uses a Sodasorb canister to absorb exhaled CO2
An ice bucket with a hollow jacket cools the gas after leaving the Sodasorb canister
A bubbler provides back pressure to keep the plastic tent blown up
The venturi is supplied with ~ 30 psi by an oxygen regulator
A purge line allows a high flow of oxygen to blow up the tent initially
Uses less oxygen
More upkeep involved
Flow through a Mark V hardhat venturi has a 20:1 flow ratio
Sodasorb
Canister
Ice
Bucket
Condensate
Ice Water
Latex
Drain
Drain
Neckseal

16. Headtents

17. Oxygen Delivery - Single Pass Head Tent
Overboard Dump Line
Oxygen
Patient
Sample Line
Oxygen Supply Regulator
Oxygen
Dump
Single pass head tent system
Employs an oxygen supply regulator to administer ~ 40 lpm of oxygen into the head tent
A dump regulator connected to the overboard dump line exhausts exhaled gas outside the chamber
Simple operation
Uses more oxygen
Overboard dump line set to 10 in H2O all depths
Regulator
Latex
Neckseal

18. Oxygen Administration by
Overboard Dump Mask
Scott masks can be used as a demand mask, free flow, hooked to overboard dump or free flow to chamber

19. Ventilator

20. Eduction Manifold Description
Outside Building
50 ft
Foxtrot
Delta
Air Amplifier
Charlie
1” pipe
Bravo
3” pipe
Each dump system was connected outside the chamber via 2.5 cm (1 in) internal diameter (ID) pipe to a 5.1 cm (2 in) ID eduction manifold. The manifold was configured as a “Y”, open to room air at its origins and connected to the building exhaust at its termination. The fan was placed between the manifold termination and the building exhaust, a 61 cm2 (4 ft2) exhaust duct.
Alpha
4 ft2 Chamber Exhaust Duct
Manifold
Inlet

21. Fire Suppression System
Relief
valve
200 psig reg.
check
valve
450 psig air
Muffler
OFF
Fire
Suppression
Tank
Pneumatic valve
Air mask
Overhead sprinklers
Manual
Pump ON
Level
indicators
Hand-held hose
Drain

22. Nitrogen Purge

23. Plantronics Headset Audio communications REDUNDANCY Headsets
Provide better communication during compression, ventilation, and decompression
Provide privacy and clear communication in emergencies
No switches inside chamber
Cross connection
allows clear communication during lock in / out procedures
Two-way speakers
Open microphone inside the chamber allows audible monitoring
EMERGENCY
Sound powered phones
Visual communications
Viewports
Closed-circuit Television

24. Telex TR-200 Wireless Intercom

25. Two-way Mic/Speaker Box
Audio communications
REDUNDANCY
Headsets
Provide better communication during compression, ventilation, and decompression
Provide privacy and clear communication in emergencies
No switches inside chamber
Cross connection
allows clear communication during lock in / out procedures
Two-way speakers
Open microphone inside the chamber allows audible monitoring
EMERGENCY
Sound powered phones
Visual communications
Viewports
Closed-circuit Television

26. Sound-powered Phone Audio communications REDUNDANCY Headsets
Provide better communication during compression, ventilation, and decompression
Provide privacy and clear communication in emergencies
No switches inside chamber
Cross connection
allows clear communication during lock in / out procedures
Two-way speakers
Open microphone inside the chamber allows audible monitoring
EMERGENCY
Sound powered phones
Visual communications
Viewports
Closed-circuit Television

27. Breathing Gas Analysis
Chamber Atmosphere
O2 (20.5% %)
CO2 (< 1.0% SEV)
Patients
O2 (> 98.0%)
CO2 ( < 1.0% SEV)
Breathing gas analysis
Documents that patients are receiving proper treatment
Vital for fire safety and personnel safety
Helps identify problems with gas delivery equipment

28. Breathing Gas Analysis
Chamber atmosphere
Maintained via ventilation of the chamber, oxygen addition, and CO2 scrubbing
Patients
Breathing gas analysis performed at least every 30 min
Oxygen and carbon dioxide levels checked to ensure oxygen delivery equipment is performing properly

29. Patient Monitoring

30. Monitoring Connections Inside the Chamber

31. Defibrillator

32. Transcutaneous Oxygen Monitors

33. Suction

34. Medical Lock

35. Hyperbaric Oxygen Therapy Program
Each year, 300 patients breathe 100% oxygen at about 2 times atmospheric pressure
13 UHMS approved conditions including air embolism, decompression sickness, CO poisoning, gas gangrene, problem wounds

36. Education Program Graduate students Intern & resident training
12 month Diving & Hyperbaric Medicine Fellowship (2 per year)
Semester course in the “Physiology & Medicine of Extreme Environments”

37. Research Program Supporting agencies
National Heart, Lung, Blood Institute
National Aviation & Space Agency
Navy, Army, Air Force
National Oceanographic & Atmospheric Administration
Divers Alert Network
Commercial diving companies

38. Saturation Diving to 2,250 Feet (1970s-80s)

39. Right Heart Bubbles LV RV LA RA

41. Flying After Diving
Recreational Diving High Altitude Parachuting (Divers Alert Network) (Army Special Forces)

42. ‘Combat Edge’ Positive Pressure Suit

43. NASA Extravehicular Activity (EVA)

44. O2 Breath-Hold Diving

45. Differential Gene Expression
Affymetrix U133A chip measures 14,000 genes per sample
Response to decompression stress (ONR)
Genetic predisposition to IPE (NAVSEA)
The external environment effects the internal environment.

46. Immersion Pulmonary Edema
Sudden dyspnea, hemoptysis during swim/dive. Can be fatal
Divers, triathletes, Navy trainees (NEDU, BUD/S)
Pathophysiology may be exaggerated increase in pulmonary vascular pressures during immersed exercise in cold water

47. Biochemical Modification of Susceptibility to Mountain Sickness (DARPA)
Can adaptation to altitude be accelerated by a combination of several drugs?
Can exercise performance be improved?
Increase systemic blood flow without increasing pulmonary blood flow?
Initial tests in mice, then humans